This invention relates to means for the characterisation of magnetic materials by measurement of their magnetic characteristics. The invention is particularly, but not exclusively, suitable for the characterisation of high energy permanent magnets.
Permanent magnets are steadily becoming more commonplace in both domestic and industrial applications and magnetic performance is being improved by the use of new materials such as rare earth/iron materials, for example neodymium-iron-boron. Such new materials have extremely high values of intrinsic coercivity, to the extent that they cannot be characterized by traditional techniques. In order to measure the complete hysteresis loop of such materials, from which the magnetic characteristics may be deduced, an external field sufficient to produce a flux density up to 15 Teslas or greater may be required; this requirement will undoubtedly increase further as new generations of magnetic materials, for example samarium-iron-nitride, are developed.